CenterPoint Energy reports that thousands of customers are in the dark this morning with the first wave of storms moving through the Houston area.

An initial report of nearly 14,000 customers quickly rose. CenterPoint reported 16,260 without power as of 6:21 a.m. on its interactive website. By 8 a.m., power had been restored to thousands of customers. Click here for updates every 15 minutes.

Also at 8 a.m., the National Weather Service in Houston/Galveston issued a flood advisory for southern Liberty County, along with Chambers, Brazoria and extreme east-central Fort Bend County. Harris and northwestern Galveston counties also are under the flood advisory.

The hazard also extends to neighborhoods ranging from Kemah and Clear Lake to Midtown and Houston's Third and Fourth wards, the Weather Service says.

Houston TranStar reported multiple wrecks before dawn as lightning and rain pelted the area. It was not clear if weather played a direct role in any of the incidents. The most severe storms are expected between 1 p.m. and 4 p.m. today in South Texas.

In Central Texas, some homes along rain-swollen rivers have been evacuated and schools delayed opening amid flooding and high-water rescues.

Emergency personnel in helicopters and boats have rescued people stranded in vehicles and stuck in trees during storm-related flooding in Central Texas.

The Hays County Sheriff's Office had no immediate reports of injuries Thursday.

A spokesman for Austin-Travis County Emergency Medical Services says a helicopter hoisted four people to safety. Warren Hassinger says the individuals were trapped in a rural area near Buda. He had no immediate additional details.

EMS boats were used for rescues in the Austin area. Austin Energy says about 6,400 customers lost electricity from storms since Wednesday night.

Evacuations were ordered along flooded creeks in nearby San Marcos and Wimberley. Schools in Wimberley, San Marcos and Lockhart closed Thursday.